A tool holder of the type in question is known from DE 40 19 506 A1. It has a main body and a holding pin onto which a rotary tool constructed as a cutting head and having a corresponding holding bore can be placed. A channel for transporting a coolant and/or lubricant and opening at the outer circumference of the holding pin is arranged in the tool holder. The coolant and/or lubricant is then transported to the cutters of the cutting head via a plurality of coolant bores in the cutting head. The rotary tool is mounted by means of a bolt that is screwed at the front end face of the holding pin into a corresponding centrally arranged mating thread in the holding pin, thus tensioning the rotary tool against the tool holder. In order to conduct coolant and/or lubricant to the cutting edges of the rotary tool, at least one channel for the coolant and/or lubricant is arranged in the annular ridge between the internal thread and the external thread. Particularly for smaller tool holders with smaller diameters of the holding pin, the rigidity and strength is additionally reduced by these coolant and/or lubricant channels, and therefore breakage cannot be reliably avoided. Angled bores must be introduced into the holding pin in order to produce these channels, which is extremely expensive. Furthermore, the hardening of the holding pin, which is usually necessary, is hampered by the small wall thicknesses in the coolant bore area, since stress cracks can easily form.